Improved process for purifying and reducing- magnetic ores of iron



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JOHN Y. SMITH, or rirrsnune, PENNSYLVANIA.

Letters Patent No. 104,220, dated J une 14, 1870; antedated June 3,1870.

The Schedule referred to in these Letters Patent and making part of thesame.

To all whom it may concern:

Be it known that I, JOHN 1. SMITH, of Pittsburg, in the county ofAllegheny and State of Pennsylvania, have invented an Improved Processfor Reducing the Pulverized Magnetic Ores of Iron in the manufacture ofcast-iron, wrought iron, and steel.

The following description will enable persons skilled in the art toreduce my improved process to practice.

What are known as sand ores of iron are found in large quantities invarious localities, and their use for conversion has been impossible inordinary blast furnaces, (except insmall qnantities,) while in theirnative state, both by reason of the difficulty of removing foreignimpurities with which they are mingled, and by reason of the lightnessof the particles, which causes them to be carried away by the force ofthe blast, or burned by the intensity of the heat.

To obviate these difficulties, they have sometimes been concreted intoblocks or lumps, and then subjected to treatment. But this concretioninto masses is expensive, and subject also to the further expense ofreducing masses so agglomerated that the heat has not ready access tothe particles.

These ores are commonly black oxide of iron, and highly magnetic, and,as found in the beds in which they are deposited, are mingled with sandor other impurities, which require to be removed.

Other magnetic ores may be used, which are reduced'to a powdered orgranulated state, or non-magnetic ores, by familiar processes, may beconverted 'into magnetic ores, and powdered or reduced to a granularform.

It is apparent that any ores in this condition may be used as well asnative sand ores.

This part of the process I propose to accomplish by means of magnets,which, acting upon the magnetic particles, hold them while a. blast ofair or stream of water removes the foreign matter upon which themagnetic force does not act.

A machine for that purpose is fully set forthin the specification anddrawings in another application filed herewith, to which reference isherein made, and which need not be fully set forth herein.

Other machines, for the same purpose, employing magnets differentlyarranged, have been patented in this country and in England.

Among others I will refer to the American patent to Francois A. H. LaRue and Chas. Panet, dated January 26,1i869, and the English patent toChas. A. B. Ohenot, or 1854:, numbered 658, as more or less perfectlyperf rming the purpose desired, viz: The separation of the particles ofiron ore from the foreign substances mingled therewith.

In this patent I do not desire...to confine my claims to the use of anyparticular TlliLc-JlllB for the purpose of separation, but include theuse of particles of magnetic iron ore separated by any known'magneticmachine.

The second part of my process relates to the reduction of the ores thusobtained.

To avoid the ditliculties already stated as attending the treatment ofsuch ores in ordinary furnaces, I use a crucible furnace, in which theore may be reduced by the action of heat applied to the exterior surfaceof the crucible, and transmitted through the crucible to the ore placedwithin the same. By this means the particles of ore are not exposed tothe current of the blast, and the heat may he so regulated as not toburn them.

I have shown in another specification, herewithfiled, a crucible furnaceespecially adapted to this use", and to that specification and theaccompanying drawings I herein make reference for a more fullunderstanding thcreof.

I do not, however, propose to confine myself in this patent to the useof any particular furnace, claiming my process wherever a crucible isused, in a furnace, for the reduction of magnetic ores, reduced to sandlike particles, and separted from foreign substances by the use ofmagnets.

I, however, regard the furnace invented by myself, as set forth in saidspecification, as being the best known mode of reducing said granulatedores, because in that furnace I provide for the proper medication of theorcs by mixing them with such known substances as are employed bypersons skilled the art of manufacturing iron and steel, for theirproper timing, and the carbonization thereof to the extent necessary forproducing iron or steel of a certain required property.

This part of the process is carried on in retorts placed across thechamber, through-which the waste heat ascends in its passagefrom thecombustion-chamher to the stack; and the ores thus prepared are then tobe passed from the retorts to the crucible through an air-chamber abovethe crucible, into which the gaseous products of combustion cannotenter, so that the entire process of treating and smelting the ore isconducted without contact with said gaseous products, whereby I am ableto accomplish definite results, as no uncertain quantities need enterinto the operation to disturb the result. In this furnace the moltenmetal and slag are drawn from the crucible by tapping the same in thesame manner as in ordinary enpola furnaces.

Having fully explained my improved process for reducing pulverizedmagnetic ores of iron,

\Vhat I claim as my invention, and desire to secure by Letters Patent,is---- 1. The process for reducing such ores by first scparating themagnetic ores from foreign impurities, by the action of amagnetic-machine, and subsequently smelting said ores so separated in acrucible-furnace, substantially as set forth.

2. Such a process consisting in first separating the magnetic ores fromforeign substances by the action of a magnetic-machine, and afterwardtreating said ores in a furnace, in which they may be medicated,roasted, and reduced, without coming into contact with the gaseousproducts of combustion evolved in heating the furnace, substantially asset forth.

In testimony whereof I have signed my name to this specification in thepresence of two subscribing witnesses.

JOHN Y. SMITH.

Witnesses:

B. EDW. J. Ens, R. MASON.

